Optical diffuser for a portable light

Patent metadata

Field	Value
Publication number	US-10533727-B2
Application number	US-201815993177-A
Country	US
Kind code	B2
Filing date	May 30, 2018
Priority date	Mar 10, 2014
Publication date	Jan 14, 2020
Grant date	Jan 14, 2020

Abstract

An optical diffuser for a light may comprise an optical body having a substantially flat base at one end thereof and a complex lens structure at the opposing end thereof. The complex lens may have a plurality of curved optical surfaces and may produce a beam of light having a non-uniform light intensity. The optical diffuser may be attached to a light by a holder, and the holder may be movable on the light to place the optical diffuser in front of a light source.

First claim

What is claimed is:

1. An optical diffuser for a portable light comprising:
an at least partially cylindrical optically clear body having a substantially flat base at an end for receiving light from a light source and having a complex lens structure at an end distal the substantially flat base, the at least partially cylindrical optically clear body defining a central axis between the substantially flat base and the complex lens structure;
the complex lens structure including a central conical recess and at least one raised annular part defining a plurality of frustro-conical surfaces coaxial with the central axis and having sloping sides,
wherein the sloping sides define optical surfaces including:
a surface that is internally reflective and a surface that is an optical exit through which light exits the complex lens structure, and/or
a surface that is both internally reflective and an optical exit, and

wherein the complex lens structure provides a beam of light having a broad beam width and a non-uniform intensity.

2. The optical diffuser for a portable light of claim 1 wherein the complex lens structure comprises:
a side surface of said at least partially cylindrical optically clear body providing a first optical exit surface;
a first internally reflective one of the plurality of frustro-conical surfaces for directing light through the first optical exit surface;
a second one of the plurality of frustro-conical surfaces defining a second optical exit surface; and
the central conical recess defining an internally reflective conical surface for directing light through the second optical exit surface.

3. The optical diffuser for a portable light of claim 2 wherein the complex lens structure further comprises:
a third one of the plurality of frustro-conical surfaces defining a third optical exit surface; and
a third internally reflective one of the plurality of frustro-conical surfaces for directing light through the third optical exit surface.

4. The optical diffuser for a portable light of claim 1 wherein the complex lens structure comprises:
a first one of the plurality of frustro-conical surfaces defining a first optical exit surface; and
a first internally reflective one of the plurality of frustro-conical surfaces for directing light through the first optical exit surface.

5. The optical diffuser for a portable light of claim 4 wherein:
the first internally reflective one of the plurality of frustro-conical surfaces defines a second optical exit surface; and
the first one of the plurality of frustro-conical surfaces directs light through the second optical exit surface.

6. The optical diffuser for a portable light of claim 1 wherein the plurality of frustro-conical surfaces of the complex lens structure comprise: a parabolic surface, a hyperbolic surface, a concave surface, a convex surface, or a combination thereof.

7. The optical diffuser for a portable light of claim 1 wherein the substantially flat base has a convex lens at a part thereof proximate the central axis.

8. The optical diffuser for a portable light of claim 1 wherein the beam of light produced by the complex lens structure includes light emanating at a half-cone angle of about 55° or greater relative to a central axis of the complex lens structure.

9. The optical diffuser for a portable light of claim 1 wherein the beam of light produced by the complex lens structure includes light emanating at half-cone angles of about 0°, about 55°, about 70° or 75°, and about 90° relative to a central axis of the complex lens structure.

10. The optical diffuser for a portable light of claim 1 further comprising: a mount for movably mounting said optical diffuser over a face of a housing from which at least one light source emits light, wherein the mount is configured to be movable to place the optical diffuser in a first position in front of the at least one light source for passing the light emitted thereby and to place the optical diffuser in a second position not in front of the at least one light source.

11. The optical diffuser for a portable light of claim 10 wherein the mount for movably mounting said optical diffuser over the face of the housing includes:
a holder having a “C” shape with the distal ends of the C-shaped holder movably engaging the housing; or
at least one flange on the at least partially cylindrical optically clear body of said optical diffuser for movably engaging a groove of the housing; or
a holder having a “C” shape with the distal ends of the C-shaped holder movably engaging the housing and at least one flange at least one flange on the at least partially cylindrical optically clear body of said optical diffuser for movably engaging a groove of the housing.

12. The optical diffuser for a portable light of claim 1 further comprising: a holder movable on a housing, wherein said optical diffuser is retained by said holder to be movable on the housing.

13. The optical diffuser for a portable light of claim 12 wherein:
said holder has a “C” shape with the distal ends of the C-shaped holder movably engaging the housing; or
said optical diffuser includes at least one flange for movably engaging a groove of the housing; or
said holder has a “C” shape with the distal ends of the C-shaped holder movably engaging the housing and said optical diffuser includes at least one flange for movably engaging a groove of the housing.

14. The optical diffuser for a portable light of claim 1 wherein the at least partially cylindrical optically clear body comprises: a glass, a clear plastic, a polycarbonate, a polystyrene, or an acrylic.

15. The optical diffuser for a portable light of claim 1 wherein the at least partially cylindrical optically clear body comprises an optical material having an index of refraction of about 1.5.

16. The optical diffuser for a portable light of claim 1 wherein the complex lens structure comprises:
a side surface of said at least partially cylindrical optically clear body providing a third optical exit surface; and
a second internally reflective one of the plurality of frustro-conical surfaces for directing light through the third optical exit surface.

17. An optical diffuser for a portable light comprising:
an at least partially cylindrical optically clear body having a substantially flat base at an end for receiving light from a light source and having a complex lens structure at an end distal the substantially flat base, the at least partially cylindrical optically clear body defining a central axis between the substantially flat base and the complex lens structure;
the complex lens structure including a central conical recess and at least one raised annular part defining a plurality of frustro-conical surfaces coaxial with the central axis and having sloping sides, wherein the sloping sides define optical surfaces that are internally reflective or that are optical exit surfaces through which light exits the complex lens structure or that are internally reflective optical surfaces and optical exit surfaces, and wherein the complex lens structure provides a beam of light having a broad beam width and a non-uniform intensity;
wherein the complex lens structure comprises:
a first one of the plurality of frustro-conical surfaces defining a first optical exit surface; and
a first internally reflective one of the plurality of frustro-conical surfaces for directing light through the first optical exit surface; and
wherein: the first internally reflective one of the plurality of frustro-conical surfaces defines a second optical exit sur

Assignees

• Streamlight Inc

Inventors

• Worman William D
• Boris Thomas D

Classifications

• F21V7/0091 Primary

  using total internal reflection · CPC title

• F21V13/045

  for portable lighting devices · CPC title

• F21L4/005

  the device being a pocket lamp (F21L4/022, F21L4/045, F21L4/085 take precedence) · CPC title

• F21Y2115/10

  Light-emitting diodes [LED] · CPC title

• F21V23/0414

  specially adapted to be used with portable lighting devices · CPC title